Process of incorporating rubber with cellulose derivatives



I KoDrawingy Application filed December 22, 1 931 Serialfliibll5$2,67l, ear iil HGrat firitain December 26,

i a Patented June 4 [UNITED STATES a riaocnss or coar imme 'nnnerm wrri'rjcnnruhdsn pmtrvk'rrvnsi This invention relates to themanufacture "of leather and rubber substitutes produced by incorporatin rubber into cellulose derivatives such as,

and cellulose acetate. e n y e According to this inventiomarubber solution is mixed with a plastic, ;more or less viscous mass prepared by precipitating a cellulose derivative from a solution of itcon-j taining at least one plasticizer either in sus pension or dissolved and capable of being precipitatedtogether with thefcellulose de-- rivative,by adding to the solution a precipiftating liquid which is misciblefwith the sol vent (or atleast one of the solventsif more lthan oneis used) of the cellulose derivative.

The precipitateofcellulose derivativeand plasticizeri andvany other softening or like 1 :agent whichmay have been addedis obtained i which contains in veryfinedistribution a small quantity of a liquid composed partly e of the precipitating agent and'partl ofthe solvent orsolvents, used for making tli lose solution. i f a v a e To facilitate the mixture of the rubber i with the cellulose paste and to ensureor enhance the coherenceof theproduct, the rubber may be dissolved in aisolvent or a mixture of solvents which isiniscible either with in the form of a more oriless viscous paste the precipitating agent used for precipitating f the cellulose derivative or-with a mixture of the precipitating agent andthe solvent or v solvents used in making up the cellulose soluazsv p 'i i The cellulose solution from which the celtion. a a

, lulose derivative is precipitated may contain anatural or synthetic resin or one or more binding or dispersing agents which are: miscible with or soluble inthe precipitating agent used for precipitating the cellulose derivative or with amixtureofthe precipitating agent and the'solvent or solvents used'in more of these binding or 'dispersing agents making up the solution of cellulose derivative.

Withoutconfining the invention to one or the following havebeen foundsuitable: dextrin, glucose, grape-sugar, cellulose ethers, glues of animal, vegetable or synthetic origin,

or instance, cellulose nitrate long as they are substantially non-solvents for the cellulose derivative and the plasticizerandas long as they conform, with'there-f quirements as to miscibility defined above.

The plasticizers which are precipitated.together. with the cellulose derivative maybe,

or instance, tricresyl phosphate, particulariunn'rriv BAN DLi, orronnon, niverAnn, mm CLOTH COMPANY, LIMI ED, 01?. Lonnoiv, ENGLAND, nasnrr snecenr nr gelatin,tagar-agar, alkali silicate, drying or the precipitat lyfinthe case of cellulose nitrate and triacetin and the esters of phenolsor poly-phenols, pari ticularly in" the case of cellulose acetate. Nonsolvent softening mediums may be added. It isadvantageous that the plasticizer should be asolvent of the cellulose derivative and should be one of the solventsin the mix: ture which is non-miscible with the precipitating liquid.

be vulcanized.

The following examples illustrate the in vention',the parts being by weight: e (1) parts of wet nitro-cotton are diswater is added until precipitatio-n has occurred. The precipitate is removed from theliquid and transferred to a kneading machine in which it is mixedvvith asolution of 50 parts of rubber in 250 parts of benzene,

The products made by the invention may i see to which have been added 5 parts of bone a glue.

dissolved in 1000 parts of acetoneand there 200 parts of nitro cellulose are added 52 parts of tricresyl phosphate, i

24 parts of castor oilfand 1 part ofcarbon black. The precipitation of the solution and a the mixing of the precipitated rubber are conducted as describedin-jthe first example. I

Having thus fully described and ascerinto practical effect, what I claimis e tained thenatureof the saidinvention and i the best means I know of carrying the same A process of making a substitute for rubber orleather, comprising dissolving a cele lulose derivative in a solvent therefor, adding a plasticizerand a dis ersing agent, adding to said mixture a liqui miscible with said solvent anddispersing agent and capable of precipitating the cellulose derivative and plasticizer and kneading the precipitate while in a viscous state with rubber dissolved in a solvent therefor. I

In testimony "whereof I have signed my name to this specification.

1 MARTIN :BANTDLI; 

